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c8b2ef05f4
The previous macro implementations just cast the argument to a target type but did not check whether the input type was appropriate. The function implementation can do better type checking of the input type. For the *GetDatumFast() macros, converting to an inline function doesn't work in the !USE_FLOAT8_BYVAL case, but we can use AssertVariableIsOfTypeMacro() to get a similar level of type checking. Reviewed-by: Aleksander Alekseev <aleksander@timescale.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/flat/8528fb7e-0aa2-6b54-85fb-0c0886dbd6ed%40enterprisedb.com
89 lines
2.9 KiB
C
89 lines
2.9 KiB
C
/*-------------------------------------------------------------------------
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*
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* varbit.h
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* Functions for the SQL datatypes BIT() and BIT VARYING().
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*
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* Code originally contributed by Adriaan Joubert.
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*
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* Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* src/include/utils/varbit.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef VARBIT_H
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#define VARBIT_H
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#include <limits.h>
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#include "fmgr.h"
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/*
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* Modeled on struct varlena from postgres.h, but data type is bits8.
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*
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* Caution: if bit_len is not a multiple of BITS_PER_BYTE, the low-order
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* bits of the last byte of bit_dat[] are unused and MUST be zeroes.
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* (This allows bit_cmp() to not bother masking the last byte.)
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* Also, there should not be any excess bytes counted in the header length.
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*/
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typedef struct
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{
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int32 vl_len_; /* varlena header (do not touch directly!) */
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int32 bit_len; /* number of valid bits */
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bits8 bit_dat[FLEXIBLE_ARRAY_MEMBER]; /* bit string, most sig. byte
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* first */
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} VarBit;
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/*
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* fmgr interface macros
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*
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* BIT and BIT VARYING are toastable varlena types. They are the same
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* as far as representation goes, so we just have one set of macros.
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*/
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static inline VarBit *
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DatumGetVarBitP(Datum X)
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{
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return (VarBit *) PG_DETOAST_DATUM(X);
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}
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static inline VarBit *
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DatumGetVarBitPCopy(Datum X)
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{
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return (VarBit *) PG_DETOAST_DATUM_COPY(X);
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}
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static inline Datum
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VarBitPGetDatum(const VarBit *X)
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{
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return PointerGetDatum(X);
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}
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#define PG_GETARG_VARBIT_P(n) DatumGetVarBitP(PG_GETARG_DATUM(n))
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#define PG_GETARG_VARBIT_P_COPY(n) DatumGetVarBitPCopy(PG_GETARG_DATUM(n))
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#define PG_RETURN_VARBIT_P(x) return VarBitPGetDatum(x)
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/* Header overhead *in addition to* VARHDRSZ */
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#define VARBITHDRSZ sizeof(int32)
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/* Number of bits in this bit string */
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#define VARBITLEN(PTR) (((VarBit *) (PTR))->bit_len)
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/* Pointer to the first byte containing bit string data */
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#define VARBITS(PTR) (((VarBit *) (PTR))->bit_dat)
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/* Number of bytes in the data section of a bit string */
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#define VARBITBYTES(PTR) (VARSIZE(PTR) - VARHDRSZ - VARBITHDRSZ)
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/* Padding of the bit string at the end (in bits) */
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#define VARBITPAD(PTR) (VARBITBYTES(PTR)*BITS_PER_BYTE - VARBITLEN(PTR))
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/* Number of bytes needed to store a bit string of a given length */
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#define VARBITTOTALLEN(BITLEN) (((BITLEN) + BITS_PER_BYTE-1)/BITS_PER_BYTE + \
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VARHDRSZ + VARBITHDRSZ)
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/*
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* Maximum number of bits. Several code sites assume no overflow from
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* computing bitlen + X; VARBITTOTALLEN() has the largest such X.
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*/
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#define VARBITMAXLEN (INT_MAX - BITS_PER_BYTE + 1)
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/* pointer beyond the end of the bit string (like end() in STL containers) */
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#define VARBITEND(PTR) (((bits8 *) (PTR)) + VARSIZE(PTR))
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/* Mask that will cover exactly one byte, i.e. BITS_PER_BYTE bits */
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#define BITMASK 0xFF
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#endif
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